1. Field of the Invention
The present invention relates to a lens-fitted photographic film unit, and more particularly to a photographic film unit of which an incorporated component is easily removed when the film unit is disassembled.
2. Description Related to the Prior Art
Lens-fitted photographic film units (hereinafter referred to as film units) are now on the market, e.g. under a trademark "Quick Snap" (manufactured by Fuji Photo Film Co., Ltd.), which are a single-use camera preloaded with photographic film. These film units make it possible to take pictures whenever desired without buying or carrying an expensive and heavy camera. Because the film unit can take pictures of sufficient quality in spite of its low cost, in spite of its low cost, various types of film units have been provided and marketed.
Such a film unit is disclosed in U.S. Pat. Nos. 4,884,087 and 4,972,649 and Japanese Patent Laid-Open Publ. No. 3-39734 and has a film housing of which a front cover and a rear cover are secured to a main assembly, in which assembly a taking lens, a film wind-up wheel, a shutter mechanism and a wind-up stopping mechanism are incorporated. The wind-up stopping mechanism is adapted to prevent the wind-up wheel from rotating when the film is fed one frame per exposure by rotation of the wind-up wheel. The main assembly is loaded in a light-tight fashion with a 135-type photographic film in a cassette as defined by ISO code 1007, 1979 version.
The main assembly is provided with a film supplying chamber and a film take-up chamber formed on opposite horizontal sides of the taking lens. The unexposed film is wound in a roll and contained in the film supplying chamber. A user who has purchased the film unit winds up the film frame by frame at each exposure on a spool in a cassette contained in the film take-up chamber. The film unit in its entirety is forwarded to a photo laboratory when the whole strip of the film is exposed. An operator at the laboratory unloads the cassette containing the exposed film from the film unit and subjects it to development and printing in accordance with conventional photographic processing techniques. The user receives photoprints and a negative film but does not receive the film housing of the film unit.
The film housing after processing has heretofore been destroyed and discarded as waste. But there is damage to the environment caused thereby, so that it is desirable to be able to recycle the film housing after processing. There could be two ways of recycling the film housing: to reassemble reusable parts as withdrawn, or to remold and regenerate moldable parts. The main assembly is usually free from dirt or damage because it is protected by the front and rear covers. It would therefore be highly advantageous, if possible, to save and reuse the main assembly incorporating the taking lens, the shutter mechanism, and the wind-up stopping mechanism.
It is disclosed in Japanese Patent Laid-Open Publ. No. 3-39734 to construct a lens-fitted film unit by following the steps of: constructing a wind-up stopping mechanism including a metallic spring together with a film containing unit of plastic integrally having the film supplying chamber for containing a roll of unexposed film and the film take-up chamber for receiving the film as wound up after exposure; combining with the film containing unit a shutter mechanism as assembled previously in a separate manner; engaging the front cover with the film containing unit to bear against the wind-up stopping mechanism and the shutter mechanism; loading the film containing unit with the film; and then securing the rear cover tightly thereto. Perhaps it would be conceivable to utilize this structure of the film unit for recycling its parts.
The film unit of this prior document is, however, disadvantageous for recycling parts, because discarding such parts will be less costly than recycling them. Although the front cover, rear cover, shutter mechanism and film containing unit can be disassembled easily, it is laborious to remove the wind-up stopping mechanism from the film containing unit and to separate and classify its parts into resin and metal. If the film containing unit is reused without removing the wind-up stopping mechanism, the reuse of the shutter mechanism as withdrawn necessitates an inspection of its performance after securing it to the film containing unit as reused. A random combination of a reused shutter mechanism and a reused film containing unit causes additional errors in dimensions, which might influence badly the performance of the recycled film unit, e.g. the shutter speed.